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WASTEWATER CLASS B TEXAS 2026
UPDATED ACTUAL EXAM WITH
CORRECT SOLUTIONS.
1. The name of the State Agency responsible for enforcing
pollution control laws in Texas - correct answer- Texas
Commission of Environmental Quality
2. The term pathogenic means - correct answer- Capable of
causing disease
3. The minimum separation between sewer lines and potable water
lines is - correct answer- 9 feet
4. A licensed wastewater operator is a professional - correct
answer- consistently does best job possible, practices personal
safety, strives to improve job knowledge, strives to keep the
plant and collection system in the best appearance and working
order
5. An important step in testing a sample for Total Suspended
Solids is - correct answer- Filtering a sample
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6. The Biochemical oxygen Demand (BOD) of a sample is based
on - correct answer- Measuring the dissolved oxygen (DO) used
7. The results of Biochemical Oxygen Demand (BOD) sample
taken at a treatment plant tells the operator - correct answer-
How the plant was operating 5 days ago
8. Which of the following are dangerous gasses that are likely to
be present in lift stations and manholes? - correct answer-
Natural gas, gasoline fumes, hydrogen sulfide and carbon
dioxide
9. A preferred hydraulic method of cleaning sewer lines is - correct
answer- Hydro Jet Cleaner
10. Ways to reduce bad odors coming from a collection
system - correct answer- routinely cleaning slow running or low
flow lines, adding chlorine or hydrogen peroxide to the
collection system
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11. Types of pipe that are commonly used in wastewater
collection system - correct answer- ductile iron, Poly Vinyl
Chloride (PVC)
12. Before entering a confined space a worker should -
correct answer- Use approved monitoring device and check
for the presence of dangerous gasses, ventilate the space
with a blower, wear a safety harness and attach a life line
13. A properly designed and operated primary
sedimentation tank should remove percent of incoming
BOD - correct answer- 30-40%
14. Devices that may be used to determine the level of sewage
in a lift station - correct answer- air bubbler, floats, electrodes,
Acoustic (sonic)
15. What is the most important role of aerobic bacteria in the
16. treatment of wastewater? - correct answer- decompose
organic matter
17. The hydraulic loading of a trickling filter may be
determined by - correct answer- flow rate and filter area
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18. These can be used to dewater sludge - correct answer-
belt press, drying beds, solid bowl centrifuge, gravity
thickener
19. Most important to providing adequate sewage
treatment in a stabilization pond - correct answer- sunlight,
algae, bacteria and time
20. Offensive and objectionable odors which sometimes occur
in trickling filters usually indicate - correct answer- septic
conditions are present
21. Dissolved Oxygen (DO) in aeration tank of an activated
sludge plant should be maintained at or about - correct answer-
2 to 4 mg/L
22. Contributes to the infiltration in a collection system -
correct answer- breaks in the main lines, high ground water
levels, heavy rains, hydro jet cleaning plugged mains
23. When a centrifuge pump loses prime the - correct answer-
pump is no longer moving liquid
WASTEWATER CLASS B TEXAS 2026
UPDATED ACTUAL EXAM WITH
CORRECT SOLUTIONS.
1. The name of the State Agency responsible for enforcing
pollution control laws in Texas - correct answer- Texas
Commission of Environmental Quality
2. The term pathogenic means - correct answer- Capable of
causing disease
3. The minimum separation between sewer lines and potable water
lines is - correct answer- 9 feet
4. A licensed wastewater operator is a professional - correct
answer- consistently does best job possible, practices personal
safety, strives to improve job knowledge, strives to keep the
plant and collection system in the best appearance and working
order
5. An important step in testing a sample for Total Suspended
Solids is - correct answer- Filtering a sample
,2 | Page
6. The Biochemical oxygen Demand (BOD) of a sample is based
on - correct answer- Measuring the dissolved oxygen (DO) used
7. The results of Biochemical Oxygen Demand (BOD) sample
taken at a treatment plant tells the operator - correct answer-
How the plant was operating 5 days ago
8. Which of the following are dangerous gasses that are likely to
be present in lift stations and manholes? - correct answer-
Natural gas, gasoline fumes, hydrogen sulfide and carbon
dioxide
9. A preferred hydraulic method of cleaning sewer lines is - correct
answer- Hydro Jet Cleaner
10. Ways to reduce bad odors coming from a collection
system - correct answer- routinely cleaning slow running or low
flow lines, adding chlorine or hydrogen peroxide to the
collection system
,3 | Page
11. Types of pipe that are commonly used in wastewater
collection system - correct answer- ductile iron, Poly Vinyl
Chloride (PVC)
12. Before entering a confined space a worker should -
correct answer- Use approved monitoring device and check
for the presence of dangerous gasses, ventilate the space
with a blower, wear a safety harness and attach a life line
13. A properly designed and operated primary
sedimentation tank should remove percent of incoming
BOD - correct answer- 30-40%
14. Devices that may be used to determine the level of sewage
in a lift station - correct answer- air bubbler, floats, electrodes,
Acoustic (sonic)
15. What is the most important role of aerobic bacteria in the
16. treatment of wastewater? - correct answer- decompose
organic matter
17. The hydraulic loading of a trickling filter may be
determined by - correct answer- flow rate and filter area
, 4 | Page
18. These can be used to dewater sludge - correct answer-
belt press, drying beds, solid bowl centrifuge, gravity
thickener
19. Most important to providing adequate sewage
treatment in a stabilization pond - correct answer- sunlight,
algae, bacteria and time
20. Offensive and objectionable odors which sometimes occur
in trickling filters usually indicate - correct answer- septic
conditions are present
21. Dissolved Oxygen (DO) in aeration tank of an activated
sludge plant should be maintained at or about - correct answer-
2 to 4 mg/L
22. Contributes to the infiltration in a collection system -
correct answer- breaks in the main lines, high ground water
levels, heavy rains, hydro jet cleaning plugged mains
23. When a centrifuge pump loses prime the - correct answer-
pump is no longer moving liquid
